Shred both types of cheese and toss together in a bowl. Remove ½ cup of cheese for topping and set aside. Melt butter in saucepan over medium heat. Stir in combined cheeses and heavy cream; stir constantly until cheese melts and sauce is smooth.

Stir in sausage and cooked macaroni. Pour mixture into a greased 2-quart baking dish. Sprinkle reserved ½ cup of cheese over top. Bake 20-25 minutes or until edges are bubbling.